Health & Medicine

Does Pot Really Lower IQ? New Study Suggests Otherwise

Catherine Griffin
First Posted: Jan 14, 2013 05:03 PM EST

When a study was released in the Proceedings of the National Academy of Sciences last summer, parents were worried. After 1,037 participants were tested, the study found that those who had become dependent on pot by the age of 18 showed a drop in IQ between the ages of 13 and 38. With the legalization of recreational marijuana in Colorado and Washington, it is not surprising that the report disturbed so many.

New findings, though, suggest that the conclusions of this study may be faulty. Ole Rogeberg of the Ragnar Frisch Center for Economic Research in Oslo examined the data sets in the old study. What he found might set parents at ease. Rogeberg noted that those who started using marijuana during adolescence were more likely to have poor self-control and conduct problems in school, factors that are related to socioeconomic status rather than IQ. Numerous other studies have shown that adolescents with low socioeconomic status experience drops in their IQ into adulthood. In the end, Rogeberg concluded that this was the reason for the difference in IQ levels, rather than marijuana use.

However, even Rogeberg admits that the previous study should not be entirely discredited. It is possible that the use of marijuana did indeed have some bearing on IQ levels, though perhaps not as much as previously thought. Although the studies may not lead to a clear answer on whether or not marijuana use is dangerous to your intelligence, they do show that more research needs to be conducted.

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